Additive concentrates for distillate fuels

Abstract

An additive concentrate for incorporation into wax containing petroleum fuel oil compositions to improve low temperature flow properties comprising an oil solution containing: (A) a C30-C300 oil-soluble nitrogen salt and/or amide compound wax crystal growth inhibitor formed by reaction of alicyclic C4 to C10 carboxylic acid and long chain secondary amine; (B) an organic acid to improve the solubility of (A) in the oil, which acid includes non-linear carboxylic acids including branched or unsaturated fatty acids, aromatic acids, e.g. benzoic acid, phenols, and organic phosphorus containing acids; and (C) a copolymer of ethylene and an unsaturated ester, e.g. vinyl acetate.

What is claimed is: 
     
       1. An additive concentrate for incorporation into wax containing petroleum fuel oil compositions to improve low temperature flow properties, comprising an oil solution containing about 20 to 70 wt. % diluent oil, and 30 to 80 wt. % of an additive combination of: (A) one part by weight of a C 30  -C 300  oil-soluble diamide formed by reaction of about two molar proportions of alkyl amine having C 8  to C 30  alkyl groups with one molar proportion of a C 4  to C 10  aliphatic acyclic dicarboxylic acid;   (B) in the range of about 0.005 to 1.0 parts by weight of an oil soluble organic acid of 6 to 30 carbon atoms, and one to three acid groups, selected from the group consisting of non-linear carboxylic acid, their anhydrides, phenols, and organic acids of phosphorus; and   (C) in the range of about 0.01 to 10 parts by weight of an oil-soluble ethylene backbone distillate flow improving polymer having a number average molecular weight in the range of about 500 to 50,000 which is a copolymer consisting essentially of 3 to 40 molar proportions of ethylene per molar proportion of unsaturated ester of the general formula: ##STR3##  wherein R 1  is methyl or hydrogen, R 2  is --OOCR 4  or --COOR 4  where R 4  is a C 1  to C 28  alkyl group and R 3  is hydrogen or --COOR 4  ; and wherein said organic acid lowers the viscosity of said oil containing (A) and (C).     
     
     
       2. An additive concentrate according to claim 1, wherein the amount of (B) is in the range of about 0.01 to 0.4 parts, and the amount of (C) is about 0.03 to 5 parts. 
     
     
       3. An additive concentrate according to claim 2, in which the ethylene copolymer is an ethylene-vinyl acetate copolymer which contains from 4 to 20 molar portions of ethylene per molar portion of vinyl acetate, and has a number average molecular weight from 1,000 to 20,000. 
     
     
       4. An additive concentrate according to claim 3, in which the diamide is obtained by the reaction of maleic anhydride with secondary di(hydrogenated tallow) amine. 
     
     
       5. An additive concentrate according to claim 4, in which the organic acid (B) is an aliphatic carboxylic acid. 
     
     
       6. An additive concentrate according to claim 4, in which the organic acid (B) is an aromatic carboxylic acid. 
     
     
       7. An additive concentrate according to claim 4, wherein said organic acid (B) is an alkyl or alkenyl succinic anhydride. 
     
     
       8. An additive concentrate according to claim 4 wherein said organic acid (B) is a fatty acid. 
     
     
       9. An additive concentrate according to claim 4, wherein said organic acid (B) is a phenol. 
     
     
       10. An additive concentrate according to claim 4, wherein said organic acid (B) is a phosphorus acid. 
     
     
       11. A distillate fuel oil containing said additive concentrate of claim 1, in such proportion as to give about 0.001 to 0.5 wt. % total of said (A), (B) and (C) components. 
     
     
       12. A distillate fuel according to claim 11, wherein: (A) is the diamide of maleic anhydride and secondary hydrogenated tallow amine and (C) is a copolymer of 3 to 20 molar proportions of ethylene per molar proportion of vinyl acetate having a number average molecular weight of 1000 to 6000. 
     
     
       13. An additive concentrate for incorporation into wax-containing petroleum fuel oil compositions to improve low temperature flow properties, comprising an oil solution containing about 20 to 70 weight % diluent oil, and about 30 to 80 weight % of an additive combination of: (A) about one part by weight of a diamide of maleic anhydride and secondary hydrogenated tallow amine obtained by the reaction of about 2 molar proportions of said amine per molar proportion of said maleic anhydride;   (B) 0.01 to 0.4 parts of benzoic acid; and   (C) about 0.03 to 5 parts of an ethylene vinyl acetate copolymer of 4 to 20 molar proportions of ethylene per molar proportion of vinyl acetate, such copolymer having a number average molecular weight of about 1,000 to 6,000; and wherein said benzoic acid lowers the viscosity of said diluent oil containing (A) and (C).